This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

Most fishing nets used in fish cage aquaculture are made of synthetic fibers such as polyamide (PA) and polyethylene (PE). Therefore, it is challenging to maintain the internal volume of the fish cage due to biofouling, which can increase the load on the cage or reduce dissolved oxygen levels by impeding smooth current flow. To address this issue, research has been conducted to replace conventional synthetic fiber cage nets with brass nets, demonstrating certain benefits such as improved productivity and ease of fish cage management. However, given the need for a more thorough examination of brass fishing net weaving technology and performance, this study assessed the optimal weaving method for brass fishing nets to be used in fish cages. Additionally, it provided essential data for the practical application of brass fishing nets by evaluating their weight, tensile strength, elongation, fatigue resistance, and wear resistance. The study concluded that weaving brass fishing nets using the chain link method ensures durability, ease of installation, and compact storage in a scroll-like form. Moreover, due to their superior fatigue and wear resistance properties, brass nets can offer increased utility if appropriate net diameter and length are selected to compensate for their higher weight per unit area and relatively higher cost compared to existing fiber fishing nets.

This study aimed to quantitatively analyze the risk using data from 329 safety accidents that occurred in aquaculture fisheries management vessels over the recent five years (2018-2022). For quantitative risk analysis, the Bayesian network proposed by the International Maritime Organization (IMO) was used to analyze the risk level according to the fishing process and cause of safety accidents. Among the work processes, the fishing process was analyzed to have the highest risk, being 12.5 times that of the navigation, 2.7 times that of the maintenance, and 8.8 times that of the loading and unloading. Among the causes of accidents, the hull and working environment showed the highest risk, being 1.7 times that of fishing gear and equipment, 4.7 times that of machinery and equipment, and 9.4 times that of external environment. By quantitatively analyzing the safety accident risks for 64 combinations of these four work processes and four accident causes, this study provided fundamental data to reduce safety accidents occurring in aquaculture fisheries management vessels.

This study aimed to examine the morphological characteristics and variation in main traits by comparing the growth of individuals of Ecklonia cava Kjellman (Laminariales, Phaeophyceae) under an aquaculture environment. This survey was conducted from April 2018 to November 2019 at the aquafarm in Jindo-gun, Jeollanam-do (South coast of Korea). To classify the morphology of individuals in the aquaculture farm of E. cava, we investigated fourteen morphological characteristics and calculated four ratios between the measured values. Juvenile individuals showed a simple or oblong lanceolate, and at 3-4 months, a short stipe and holdfast developed, along with a bladelet that developed into the secondary blade form. At 5-7 months, secondary blades were found to develop irregularly on the primary blade. At 8-10 months, the primary blade expanded and secondary blades elongated. At 11-12 months, the secondary blades became oblong. At 13-14 months, the thallus area expanded. At 15-16 months, tertiary blades were formed, the thallus became more complex, the stipe thickened, and the holdfast widened. At 17-18 months, secondary blades clearly developed along with lobes. At 19-20 months, tertiary blades developed and became similar to mature natural blades. In the principal component analysis (PCA), the monthly population of the first year (Q1) and that of the second year (Q2) of the cultured population were divided along PC1, which is related to secondary blade morphological characteristics and the holdfast width. Q2 and natural populations are distributed in descending order of volume in Jeju (J), East Coast (E), and South Coast (S) along PC2, which is related to primary blade and stipe morphological characteristics. The results of this study were judged to offer important criteria for the development of different varieties of E. cava.

Among Japan's agriculture, forestry, fisheries and regional revitalization plans established in June 2018, the key matters related to aquaculture include ① a new perspective on the sponge use system for the development of aquaculture and coastal fisheries, ② a comprehensive strategy for growth and industrialization of aquaculture, and ③ expansion of suitable aquaculture areas. There are four countermeasures including ④ research and development trends. In accordance with these key points, the Japanese government established a comprehensive strategy for aquaculture growth and industrialization by strategically setting aquaculture items in consideration of domestic and international demand, establishing a comprehensive strategy from production to sales and export, and then working in earnest to promote the aquaculture industry. This study analyzes environmental changes surrounding aquaculture in Japan and trends in fish farming and marine products, and summarizes the key points of the June 2018 Agriculture, Forestry, Fisheries and Regional Revitalization Plan to suggest measures that can be utilized in Korea’s aquaculture policy.

This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.

The development potential of the aquaculture industry is very high, but there is no financial support for investment except for the government, policy funds, fishery funds, etc. Therefore, we would like to propose a contract transaction in the aquaculture industry. This refers to a forward contract between a producer (fish farmer) and a buyer (mainly a processor or marketer) that stipulates the production and supply of fish products at a predetermined price, but it also refers to an “equity participation type” contract in which both producers and buyers can participate. In other words, it is a model in which part of the fish farm is produced in a way that meets the conditions of the buyer, and part is produced by the producer. This study aims to establish the basic contract trading process. It provides an academic approach to prevent adverse selection and moral hazard due to information asymmetry. It also provides an idea to converge the aquaculture industry with the financial industry using Pecking Order theory. By doing so, we have made it possible for venture capitalists to invest with confidence and provided a process for investors to resolve their concerns, paving the way for the aquaculture industry and the financial industry to develop together.

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

Large amounts of waste and wastewater from aquaculture have negatively impacted ecosystems. Among them, shrimp aquaculture wastewater contains large amounts of nitrogen contaminants derived from feed residues in an aerobic environment. This study isolated candidate strains from adult rockworms to treat shrimp aquaculture wastewater (SAW) in an aerobic environment. Among 87 strains isolated, 25 grew well at the same temperature as the shrimp aquaculture with excellent polymer degradation ability (>0.5 cm clear zone). Six isolates (strains AL1, AL4, AL5, AL6, LA10, and PR15) were finally selected after combining strains with excellent polymer degradation ability without antagonism. 16S rRNA sequencing analysis revealed that strains AL1, AL4, AL5, AL6, LA10, and PR15 were closely related to Bacillus paramycoides, Bacillus pumilus, Stenotrophomonas rhizophila, Bacillus paranthracis, Bacillus paranthracis, and Micrococcus luteus, respectively. When these six isolates were applied to SAW, they reached a maximum cell viability of 2.06×105 CFU mL-1. Their chemical oxygen demand (CODCr) and total nitrogen (TN) removal rates for 12 h were 51.0% and 44.6%, respectively, when the CODCr/TN ratio was approximately 10.0. Considering these removal rates achieved in this study under batch conditions, these six isolates could be used for aerobic denitrification. Consequently, these six isolates from rockworms are good candidates that can be applied to the field of aquaculture wastewater treatment.

This study aims to analyze the cost of climate change damages to laver and sea mustard aquaculture, which are considered to be highly vulnerable to climate change in Korea. For this purpose, the correlation between aquaculture production and climate factors such as water temperature, salinity, air temperature, and precipitation was estimated using a panel regression model. The SSP scenario was applied to predict the changes in production and damage costs due to changes in future climate factors. As a result of the analysis, laver production is predicted to decrease by 18.0-27.2% in 2050 and 20.6-61.6% in 2100, and damage costs are predicted to increase from 29.7-50.8 billion KRW in 2050 to 35.7-116.1 billion KRW in 2100. Sea mustard production is projected to decrease by 24.5-37.2% in 2050 and 24.0-34.5% in 2100, with similar damage costs of 41.1-61.8 billion KRW and 41.1-58.6 billion KRW, respectively. These damage costs are expected to occur in the short term as damage caused by fishery disasters such as high temperatures, and in the long term as a decrease in production due to changes in aquaculture sites. Therefore, measures such as strengthening the forecasting system to prevent high-temperature damage, developing high-temperature-resistant varieties, and relocating fishing grounds in response to changes in aquaculture sites will be necessary.

Laver aquaculture, which occupies a large proportion in the aquaculture industry in Korea, is still highly dependent on human labor. Therefore, it is necessary to study the development of an automatic system to improve the working environment and increase the efficiency of aquaculture production systems. The purpose of this study is to evaluate the economic feasibility of an improved system in a study for the loading-unloading and automatic weighing systems in laver aquaculture industry. Economic analysis of the developed unloading and automatic weighing system were implemented under various conditions to calculate more accurate benefits and costs. As a result of this study, the economic feasibility was found to be very high in the three models: net present value (NPV), benefit-cost ratio (B/C), internal rate of return (IRR). Moreover, the results of sensitivity analysis showed that the economical efficiency of the automatic loading, unloading, and weighing system in laver aquaculture was very high.

Climate change is a major global problem. Oysters, one of the most representative farmed fish in Korea, are attracting attention as candidates for blue carbon, an alternative to carbon neutrality. This study is analyzed by the SSP scenarios to determine the impact of oyster aquaculture production according to climate change. Based on the analysis, future productions of oysters are predicted by the SSP scenario. Significant differences by the SSP scenario are confirmed through predictive power tests among scenarios. Regression analysis was conducted from January 2001 to December 2014. As a result of the analysis, water temperature, water temperature quadratic term, salinity, salinity quadratic term, and month × water temperature cross term were estimated as significant variables. Oyster production which is predicted by the SSP scenario based on the significant variables from 2015 to 2022 was compared with actual production. The model with the highest predictive power was selected by RMSE and MAPE criteria. The predictive power was compared with the MDM test to determine which model was superior. As a result, based on RMSE and MAPE, the SSP1-2.6 scenario was selected as the best model and the SSP1-2.6, SSP2-4.5, and SSP3-7.0 scenarios all showed the same predictive power based on the MDM test. In conculusion, this study predicted oyster aquaculture production by 2030, not the distant future, due to the short duration of the analytical model. This study was found that oyster aquaculture production increased in all scenarios and there was no significant difference in predictive power by the SSP scenario.

안정동위원소 분석 기법(Stable isotope analysis, SIA)은 환경과학, 생태학, 지구생물화학, 법의학, 고고학 등 다양한 연구 분야에 활용되고 있다. 본 총설에서는 수산 및 양식 연구에 안정동위원 소 비 분석 기법을 활용하기 위해 필요한 배경 지식을 소개하고자 한다. 특히, 자연 값(natural abundance)을 이용하는 연구에 초점을 두었고 원소가 생물의 조직으로 통합되는 과정에서 발 생하는 분별작용(동위원소 비의 변화)에 대한 원리와 안정동위원소 비가 유용한 도구로서 어 떤 목적으로 생태, 환경학 분야에 이용되는지, 나아가 수산 및 양식 분야에 활용 가능한 예들 을 제시하고자 한다. 본 논문을 통한 안정동위원소 분야의 이해로 향후 수산학 및 양식 연구 에서 안정 동위원소 비의 다양한 활용이 기대된다.